Python 更新给定索引的列值
即使没有错误,也无法更新给定索引的数据帧的列值Python 更新给定索引的列值,python,python-3.x,pandas,series,Python,Python 3.x,Pandas,Series,即使没有错误,也无法更新给定索引的数据帧的列值 import pandas as pd dict = {'col_1': {0: 'A', 1: 'B', 2: 'C'}, 'col_2': {0: 'I', 1: 'J', 2: 'K'}, } df = pd.DataFrame(dict) my_index = [1,2] df['col_3'] = None df.loc[my_index, :].col_3 = 'X' 电流输出(df) 预期产出(
import pandas as pd
dict = {'col_1': {0: 'A', 1: 'B', 2: 'C'},
'col_2': {0: 'I', 1: 'J', 2: 'K'},
}
df = pd.DataFrame(dict)
my_index = [1,2]
df['col_3'] = None
df.loc[my_index, :].col_3 = 'X'
电流输出(df)
预期产出(df)
让我们试试
df.loc[my_index, 'col_3'] = 'X'
df
Out[14]:
col_1 col_2 col_3
0 A I None
1 B J X
2 C K X
我想你的意思是
df.loc[my_index,'col_3']='X'
Oh nice!。意外发现df.loc[my_index,:]col_3和df.loc[my_index,'col_3']返回相同的序列,但赋值的工作方式不同
col_1 col_2 col_3
0 A I None
1 B J X
2 C K X
df.loc[my_index, 'col_3'] = 'X'
df
Out[14]:
col_1 col_2 col_3
0 A I None
1 B J X
2 C K X